This program-project proposal reflects a direct outgrowth of research on the biobehavioral foundations of human language and cognition supported by NICHD-06016. It builds on the psychological principles articulated from that research and uses methods developed and proven there. However, the present proposal is not focused on language acquisition. Rather, the present proposal is comprised of six separate projects designed to elucidate the emergence of cognitive competence at it is manifest across primate species, development periods, and other grouping variables, and in correspondence with brain structure, activity and function. The present proposal also benefits from substantial overlap, complementarity, and in convergence between the separate projects, such that the scientific promise of the entire program greatly exceeds the sum of anticipated scientific gains of each of these strong individual projects. The psychological processes being investigated (attention, executive function, memory, spatial problem solving, numerical cognition, metacognition) are closely inter-related, and the study of any one process requires understanding its relation to language the other constructs. Further, cognitive competence can be studied from different levels of analysis, and the present proposal aims to elucidate the correspondence between the psychological and the neurobiological levels. The synthesis of these projects and the administration of the this team of investigators will be supported by a core. Images of brain structure and activity will benefit all of the investigations in this program-project, just as care of the non-human primates and maintenance of laboratory resource will be to the advantage of all of the proposals. Its core support and functions will ensure that the ambitious program of research proposed here is conducted in an efficient and integrative way, using our unique and limited animal resources to yield the greatest scientific gains.